Compress PDF
Compress PDFs in a dedicated browser worker with Ghostscript WebAssembly. Choose Light, Medium or Heavy image optimization, or make a bounded best-effort attempt at a target size. Vector text stays vector where Ghostscript supports it, outputs are parsed and sample-rendered, and larger results are never presented as an improvement.
- Processed locally in your browser
- No watermark
- No sign-up
- Works offline
Processed locally in your browser. Compression runs in a dedicated Ghostscript WebAssembly worker. No file is uploaded, and target sizes are best-effort—not guaranteed.
Choose a PDF or drop it here
One PDF · recommended maximum on this device: 150.0 MB
How it works
- 1Open a PDF and review the local preflight estimate.
- 2Choose a quality preset or a best-effort target size.
- 3Ghostscript compresses the document inside a dedicated WebAssembly worker.
- 4NGPDFs validates page count and renders a sample before offering the smaller result.
Your privacy
This tool runs entirely inside your browser using JavaScript and Web Workers. Your document is never uploaded to any server — you can even disconnect from the internet and keep working once the page has loaded.
Frequently asked questions
▸Can every PDF become much smaller?
No. Text-only and already-optimized PDFs may have little to save. If the result is larger, NGPDFs reports that honestly and does not offer it as a replacement.
▸Are target sizes guaranteed?
No. Target mode makes at most four progressively stronger attempts (two on constrained devices), then returns the smallest validated result and states whether the target was reached.
▸Does compression rasterize my text?
The Ghostscript pdfwrite pipeline preserves vector text where supported while downsampling and recompressing images. Some unusual PDF features may be rewritten or unsupported, so review important output before sharing.